Trace Evidence – Individual vs. Class Evidence Notes on page 27 in notebook Trace Evidence – Individual vs. Class Evidence

What is Trace Evidence? A very small piece of physical evidence that can be used to identify or link a suspect to a crime

Anton von Leeuwenhoek 1670 – Anton von Leeuwenhoek constructs first microscope Very important in analyzing trace evidence

What is Trace Evidence? Derived from Edmond Locard’s Exchange Principle Every contact leaves a trace There will be small transfer of evidence during the commission of the crime

Trace Evidence Divided into individual or class evidence

Individual Evidence Individual evidence shows an object’s uniqueness Can specifically place things to a person or a place or an object to the exclusion of all others DNA, fingerprints, some footwear impressions, bite marks, bullets

Class Evidence Class evidence can place an object to a group, but not to an individual Will include a group of suspects Examples: fibers, paint, soil, glass

Scenario A student is kidnapped on the way home from school. Her backpack is found on the side of the road. There are several strands of hair caught in the zipper. Is this individual or class evidence? Explain why.

Page 26 – Individual vs. Class Evidence Activity Case #1 Case #7 Case #2 Case #8 Case #3 Case #9 Case #4 Case #10 Case #5 Case #11 Cast #6 Case #12